BASIC COMPUTER CONCEPTS

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BASIC COMPUTER CONCEPTS
Updated 8/27/04
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Hardware vs. Software

• Hardware
• The computer equipment
• Includes printers, monitors, disk drives, etc.
• Software
• Programs which tell the computer what to do
• Examples - word processing, gradebook, tutorials,
  games, etc.

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History of Computers

• Charles Babbage - father of computer
• 1800s planned analytical engine
• ENIAC - developed at end of WW II
• 1951 - 1963 1st and 2nd generation
• very large, used unreliable vacuum tubes
• 1963 - present - 3rd and 4th generation
• smaller, faster - use transistors and integrated
  circuits

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History - Microcomputers

• Apple
• First sold in late 1970s
• Developed by Jobs and Wozniak
• IBM Personal Computers
• First sold in 1981
• Was quickly accepted by businesses
• IBM compatibles soon developed

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Computer - Social Impact

• Threat to privacy
• Reduce personal interactions
• Displace workers and change workplace
• Create two tiered society
• Computer failures cause great damage
• Artificial Intelligence
• Create a new life form
• Machines smarter than their creators

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Types of Computers Personal Computers (PC)

• Also called Microcomputers
• Available in desktop size, notebook size and
  handheld
• Can be IBM, IBM Compatible or Apple

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Types of Computers - Minicomputers

• Size of filing cabinet
• Used by small and medium size companies and
  institutions
• Operated by computer specialist
• Terminals allow many people to use

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Types of Computers - Mainframes

• Very powerful
• Very fast
• Used by large corporations and governmental
  agencies
• Operated by computer specialist

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Types of Computers- Supercomputers

• Most powerful
• Fastest
• Most expensive
• Several million dollars each
• Used only by
• Governmental agencies
• Large international corporations

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Computer Operations
Input
Processing
Output
External Storage
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Input Devices - Keyboard

• Most commonly used input device
• Ergonomic - fit natural hand placement
• Special keys
• Enter, Function, Ctrl, Alt, Num Lock, Esc

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Input Devices - Mouse

• Controls cursor on screen
• May be mechanical or optical
• Most models have a wheel for scrolling

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Input Devices - Other

• Pointers (replaces mouse on notepads)
• Track point, track ball, touch pad
• Scanner
• Digital camera
• Touch screen
• Voice

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Output Devices

• Monitor
• Printer
• Disk Drive
• Can also be input device
• Modem
• Can also be input device

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Monitors

• Made up of tiny elements called pixels
• Each row of pixels is called a scan line
• Picture is displayed by an electronic beam
  lighting up certain pixels

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Monitors - Resolution

• Resolution is how sharp and clear the picture is
• How many scan lines on the screen
• 640 x 480 is low resolution
• 1600 x 1200 is high resolution

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Monitors - Dot Pitch

• Measures the distance between pixels
• Commonly seen on monitors advertised
• .49 (not very good)
• .28 (much better)
• .26 or lower (excellent)

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Monitors - Sizes

• Screen measured diagonally
• May also measure actual viewing area
• 14 or 15 on bargain systems
• 17 has become the standard
• 19 and 21 available but are more expensive.

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Monitors - LCD

• Liquid Crystal Display
• Similar to digital watch
• Used for notebook computers
• Should be an Active Matrix Screen
• Also used in flat screen monitors
• Much thinner than regular CRT monitor
• More expensive than regular CRT monitor

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Monitors - Video Card

• Processes info to send to monitor
• Amount of video memory may speed up graphic
  intensive programs
• 32 megs general purpose
• 128 or more megs graphic intensive use
• AGP port can speed up graphics
• 3D accelerator card improves graphics

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Monitor - Buying Hints

• 17 or larger
• .28 dot pitch or better
• 32 or more megs of memory on video card

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Printers

• Laser
• Ink Jet
• Dot Matrix

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Printers - Laser

• Works similar to a copy machine
• Color printers available but more expensive
• Fast, quite, with excellent quality
• More expensive to buy and operate
• Some units scan, photocopy, and print

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Printers - Ink Jet

• Squirts small jet of ink onto paper to form
  characters
• Replaced dot matrix
• Quiet
• Does good job on color
• Good quality and reliability

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Printers - Dot Matrix

• Strikes pins against ribbon to print
• Comes in 9 and 24 pin
• Once very popular
• Now replaced by ink jet and laser

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Printers - Speed

• Measured in pages per minute (PPM)
• Laser printers range from 20-45 ppm
• Color printing is slower

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Printers - Quality of Print

• One measure is dots per inch (DPI)
• 300 dpi for general purpose uses
• 600 dpi for higher quality
• 1200 dpi for photo quality
• May have different vertical and horizontal
  resolution
• 600 x 300
• Other factors can affect quality

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Basic Processing Cycle
Central Processing Unit
Internal Memory
Data Bus
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How Information Is Stored

• Memory consist of switches which can be either on
  or off - Off0 On1
• Each on/off switch is called a bit
• Eight bits make up a byte
• It takes one byte to store a character
• Character can be letter, space, punctuation, etc.
  
• ASCII code used

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Other Memory Terms

• Byte is eight bits
• Kilobyte (KB) is approx. 1,000 bytes
• Megabyte (MB) is approx. 1million bytes
• Gigabyte (GB) is approx. 1 billion bytes

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Central Processing Unit

• Also called CPU, processor or microprocessor
• Is the brains of the computer
• Performs all computer operations

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CPU - IBM COMPATIBLES

• Many made by company called Intel
• Also made by AMD

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Pentium class processors

• Needed to run most current software
• Intel Celeron or Pentium IV
• AMD

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CPU - Clock Speed

• Number of cycles per second computer can
  operate
• Measured in megahertz (MHz)
• One MHz 1 million cycles per second
• One gigahertz(GHz)1 billion cycles
• Current speeds 2-4 GHz

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CPU - Misc.

• Performance also affected by speed of data bus
• 400-800 MHz on most current systems
• Cache can increase speed
• Stores data you will likely need next in an area
  that has faster access
• Both memory cache and disk cache used
• Should be 512 K or better

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CPU - Buying Hints

• Minimum of Pentium IV or AMD Athlon
• Minimum of 2 GHz clock speed
• Minimum of 512K of cache

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Internal Memory - RAM

• RAM - Random Access Memory
• CPU can access any location as quickly as any
  other
• Can not only read current info but also write new
  info
• Very important in determining capabilities of the
  computer system
• Computer should have at least 256 megs - 512
  preferred (can add to later)

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Internal Memory - ROM

• ROM - Read Only Memory
• Can read info Stored in ROM
• Can not write new info into ROM
• Used for internal workings of computer
• Buyer is not very concerned with ROM

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External Memory
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Floppy Drives

• Comes in 5 1/4 and 3 1/2
• All systems now only have 3 1/2
• HD - High density - comes on all current systems
• 3 1/2 - 1.44 megs

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Hard Drives

• Built into machine
• Made up of stack of platters
• Can store much more than floppy drives
• 40 gigabytes should be minimum
• Can access info much faster than floppy drive

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CD ROM

• Same as music CDs
• Are read only
• Can store over 650 megs
• All programs now only sold on CD
• Make multimedia possible
• Come in different speeds - 20x, - 50x

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DVD-ROM

• Digital Video Disk
• Can store up to 17 GB
• Can store full-length movies
• Can also read CD-ROM disk

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CD-RW DVD-RW DRIVES

• Allows you to write to disk
• Useful for
• Data backup
• Storage of large files
• Recording music and other multimedia files
• DVD-RW
• Allows you to write to both CD and DVD disk
• Still somewhat expensive

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Storage Devices - Other

• USB drive
• Very popular 64-512 MB
• Tape drive
• Similar to cassette tape
• Used for backup
• Zip drive
• 100 MB to 2 GB capacity
• Everyday use and backup

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Drives - Buying Advice

• 40 gigabyte hard drive
• One 3 1/2 high density floppy drive
• CD-RW drive
• DVD not yet essential but useful

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Expansion Slots

• Allows you to add capabilities
• Example of cards you can add
• Network card
• Modem

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Ports

• Connects computer to another device
• Parallel port
• Used primarily by printers
• Serial ports
• Modem, mouse, etc.
• SCSI - chain devices
• USB may be needed for
• Digital Cameras
• Mp3 players
• Other devices

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Networks

• Connects computers
• LAN - Local Area
• WAN - Wide Area
• Wireless
• Allows sharing of programs, files, printers, etc.
• Server is main computer

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Modems - General

• Allows 2 computers to communicate over phone
  lines
• Can be internal or external
• Can also have fax capabilities

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Modems

• Bits per second(bps) indicates speed
• Old modems - 9,600, 14,400, 28,800, 33,600
• 56,000 (56K) has becoming standard
• Ways of connecting to the Internet
• Dial-up modem used in most homes
• Cable modem uses TV cable lines
• DSL modified phone line
• T1 line used by schools, businesses, etc.

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Buying Hints Summary - Min Hardware Requirements

• 2 GHz Pentium IV Class Processor
• 256 megabytes of RAM
• 17, .28 dot pitch monitor with 32 meg card
• 40 gigabyte hard drive
• CD-RW
• 56k modem
• Ink jet or laser printer

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Buying Hints - Software Bundles

• Many systems come with software included
• Productivity
• Microsoft Works
• Microsoft Office, Lotus SmartSuite, etc
• Quicken, Money, or other financial software
• Reference
• Microsoft Encarta or Comptons encyclopedia
• Games

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Buying Hints - Service and Warranty

• Toll-free 24 hr 7 day support (800 )
• 1 year warranty on parts and labor
• Optional extended warranty
• 30 day return policy

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Buying Hints - Web Sites

• On-line computer stores
• C-Net Hardware reviews and prices from many
  vendors
• Dell - http//www.dell.com/
• Gateway - http//www.gateway.com/

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Programs

• Set of instructions to the computer
• Programming languages
• Machine language
• Assembly language
• Procedural languages
• Basic, Fortran, Cobol
• Object oriented languages
• Visual Basic, C, C, Java

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Systems Software

• Run fundamental operations
• Loading and running programs
• Saving and retrieving data
• Communicating with printers, modems, etc.
• Examples of systems software
• DOS
• Windows 3.1, 95, 98, Me, 2000, and XP
• Unix
• Linux

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Applications Software

• Helps you to accomplish a certain task
• Examples
• Word processing - memos, reports, etc.
• Spreadsheets - budgets, etc.
• Database - search, sort, select data
• Educational - simulations, practice
• Graphics - charts, diagrams
• Desktop publishing - pamphlets, etc.

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Software - Legal Issues

• Commercial software
• Can only make backup copies for yourself
• Can only use on one machine at a time
• Site license - use on more that one machine
• Shareware
• Can use - make copies and give to anyone
• Should pay if you continue to use
• Freeware can copy and use indefinitely

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Software Viruses

• Illegal code added to a program
• May spread to many computers
• Copy files from one computer to another
• Download files by modem
• E-mail attachments
• Virus may be relatively harmless
• Writes Youve been stoned on screen
• Virus may also be very damaging
• Erases everything on hard drive
• Virus may activate on a certain date

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Virus Protection

• Be careful where you copy files from
• Do not open e-mail attachments unless you are
  sure that it is safe
• Use virus protection program
• Detects and removes illegal code
• Should be updated often

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BASIC COMPUTER CONCEPTS

• End of Slide Show